Jñāneśvarī (commentary on the Bhagavadgītā) 4.165

4.165

tad viddhi praṇipātena paripraśnena sevayā
upadekṣyanti te jñānaṃ jñāninas tattvadarśinaḥ
teṃ jñāna paiṃ gā baraveṃ |
jarī manīṃ āthi āṇāveṃ |
tarī saṃtāṃ yāṃ bhajāveṃ |
sarvasveṃśīṃ ||

If you wish in your heart
to bring about that good knowledge,
then you must serve these saints
with your whole being.